In forestry, typically a part of wood raw material is used as saw timber, which is used for making boards and planks at a sawmill. In addition to this, a part of the wood raw material, such as thinning waste, as well as tree tops and branches are utilized as firewood. When making firewood, the wood raw material is sawn and split. For firewood, which is classified as solid biofuel, there exists a standard EN 14961-5, which defines different classes for firewood. In class A, for example, the cutting surface must be even and 90% of the wood must be split.
For handling wood raw material there are known different cutting and splitting machines and as the most advanced machine, a firewood processor where these functions are combined. A firewood processor comprises a saw section for sawing wood raw material and a splitting section for splitting the sawn wood raw material. A firewood processor may comprise conveyors, for conveying, for example, a log or a pole being machined or the finished chips (i.e. chopped wood).
Some firewood processors use a saw that comprises a saw chain. When using this type of a firewood processor the saw cutter (i.e. saw chain) loosens. A cutter that is too loose cuts wood in a bad position, which results in it blunting quickly. Sawing with a blunt cutter wears the cutter and slows down the sawing. When the saw chain wears, it may eventually break. The saw cutter must be tightened every once in a while in order to ensure proper operation of the saw.
Typically the saw chain is tightened by hand by loosening the securing bolts of the saw chain flange, by moving the saw chain flange and by tightening the saw chain flange into its place. Tightening the cutter causes a pause in work and thus slows the working down. Tightening by hand is done only from time to time, in which case the cutter has an optimum tightness only just after it has been tightened and it begins to loosen directly after this. Thus, the cutter becomes blunt more quickly than a cutter that has the appropriate tightness.